Socalwaterindex

This changes adds a second watering index provider: the Metropolitan Water District of Southern California.

This is probably of no use in Idaho, but quite convenient in Los Angeles. I feel more comfortable using the MWD index than an index from a hardware vendor (i.e. a competitor).

While I was at it, I wondered why the configuration change was not reflected in the main status page. Found a race condition between saveConfig (change the effective config only after it was saved successfully) and activeConfig (activates whatever is the effective config now). Also, the watering index data from the old provider should be trashed when the provider change, or else the status shows the old provider's index and the new provider's name. Hoops.